The ZWO EFW 8 × 1.25" / 31 mm (2025 version) is an improved electronic filter wheel designed for multi-band astrophotography. Its upgraded internal structure reduces the risk of light leakage, while the high-precision stepper motor ensures stable and repeatable filter positioning. The CNC-machined aluminum body provides rigidity with low weight, and the new USB-C interface delivers reliable plug-and-play connectivity with no drivers required. The wheel accommodates eight 1.25" or 31 mm filters and maintains an effective optical thickness of 20 mm, making it suitable for imaging systems with limited backfocus.

Key features

• 2025 version featuring an enhanced anti light-leak structural design
• holds 8 filters (1.25" or 31 mm)
• optical thickness: 20 mm
• USB-C interface for power and communication (120 mA @ 5 V)
• high-precision stepper motor for accurate filter indexing
• CNC-machined aluminum body; 6061 aluminum filter carousel
• fully compatible with all ZWO filters
• works with ASIAIR, ASIStudio, ASCOM, and ZWO SDK
• true plug-and-play – no driver installation required
• fully enclosed motor compartment and sealed lateral interfaces for improved light blocking

Included in the box

• ZWO EFW 8 × 1.25" / 31 mm (2025 version)
• 8-position filter carousel
• USB-A → USB-C cable
• filter mounting screws
• hex key
• user manual

Technical specifications

• model: ZWO EFW 8 × 1.25" / 31 mm (2025)
• number of slots: 8
• compatible filters: 1.25" or 31 mm
• optical thickness: 20 mm
• weight: 530 g
• power consumption: 5 V via USB-C (120 mA)
• interface: USB-C
• body material: CNC-machined aluminum
• carousel material: 6061 aluminum
• motor: high-precision stepper motor
• anti-light-leak protection: improved sealing + enclosed motor compartment
• software compatibility: ASIAIR / ASIStudio / ASCOM / ZWO SDK
• drivers: not required (plug-and-play)